PARIS—The possibility of U.S. authorities inflicting large and broad sanctions on BNP Paribas SA is a threat to the economy and the global financial system, Bank of France Governor Christian Noyer said Wednesday.

U.S. authorities are pushing BNP Paribas to pay more than $10 billion and plead guilty to allegedly violating U.S. sanctions against countries including Iran and Sudan, according to people familiar with the matter.